Communication memory for receiving control information sequentially and in parallel form for temporary storage and broadcasting on parallel bus

ABSTRACT

A design of a flexible communication device capable of reducing time and labor required for changing a communication protocol and positively eliminating an erroneous operation, and interface devices for the communication device. A communication device ( 1 ) receives from a control device ( 2 ) control information corresponding to address spaces of the control device ( 2 ) for loading into a memory ( 7 ) sequentially. A command acquisition unit ( 8 ) sequentially reads control information stored in the memory ( 7 ), and sends them to individual detection units ( 9 - 1  to  9 - m ) via a back-end bus ( 12 ). Each detection unit detects whether or not the control information match each communication protocol module corresponding to each detection unit and sends matching control information, if any, to an own communication protocol module for communication protocol processing. A communication protocol management unit ( 11 ) manages and processes, via a bus ( 13 ), data moving through connection media between communication network interfaces ( 6 -l to  6 - n ) and respectively corresponding communication terminals ( 3 - 1  to  3 - n ).

TECHNICAL FIELD

This invention relates to a communication system which has a certaincontrol device, one or more communication terminals, and a communicationdevice which connects the control device with the communicationterminals and has one or more communication protocol modules whichcontrol the one or more communication terminals based on controlinformation from the control device, and more particularly to acommunication system which can remarkably reduce time and labornecessary for changes to the communication device design based onmodifications to the communication protocol itself.

BACKGROUND ART

There exist communication systems with a communication device whichconnects a certain control device with one or more communicationterminals, and controls the one or more communication terminals based oncontrol information from the control device.

For example, FIG. 9 shows a structure of a communication systemincluding a communication device. A communication device 101 in acommunication system 100 connects with a user control device 102, acommunication network 103, an audio processing device 104 such as atelephone set, a data processing device 105 such as a router, and avideo processing device 106 through a user interface 102 a, an opticalcommunication interface 103 a, an audio interface 104 a, a datainterface 105 a, and a video interface 106 a, respectively. The opticalcommunication interface 103 a connects with the communication network103 via an optical fiber LL to implement high-speed communication. Aport 104 p of the audio interface 104 a connects with the audioprocessing device 104 through a two-wire telephone line to implementtransmission and reception of audio information. A port 105 p of thedata interface 105 a connects with the data processing device 105 suchas a LAN router, for instance, through a twisted pair cable (UTP-5) ofthe 10 BASE standard (IEEE802.3), to implement transmission andreception of data. A port 106 p of the video interface 106 a connectswith the video processing device 106 via a coaxial cable, to implementtransmission and reception of video information. The user control device102 connects with the user interface 102 a via a cable corresponding tothe user interface 102 a, i.e., a serial transfer cable such as anRS232C interface cable, for instance, to provide control informationfrom the user control device 102 to the communication device 101 as aninput.

The communication device 101 contains a communication protocol engine107 which has a communication protocol to multiplex and demultiplexinformation such as audio, data, and video for the communication network103. This communication protocol converts analog telephone signals intodigital signals, or converts digital signals into analog telephonesignals. This conversion processing includes, for instance, ringindication, off hook detection, dialing, and audio digitalization. Thiscommunication protocol also converts analog video signals into digitalvideo signals, or converts digital video signals into analog videosignals. Moreover, it multiplexes and sends information received fromthe audio processing device 104, the data processing device 105, and thevideo processing device 106 to the optical fiber LL. Conversely, itdemultiplexes information received from the optical fiber LL. It sendsinformation through the optical fiber LL to the communication network103, and receives information from the communication network 103 throughthe optical fiber LL.

The user control device 102′ sends control information to thecommunication protocol engine through the user interface 102 a, andcontrols communication among the communication network 103, the audioprocessing device 104, the data processing device 105, and the videoprocessing device 106. For example, it can control the activation ordeactivation of the optical communication interface 103 a, the audiointerface 104 a, the data interface 105 a, and the video interface 106a, the loopback processing of all interfaces 104 a to 106 a, and settingof bandwidth used for audio, data, and video on the optical fiber LL.

More concretely, as described in FIG. 10, contents of registers RR inthe user interface 102 a correspond to communication protocol modules107 a to 107 d in the communication protocol engine 107. Controlinformation FA which controls the activation or deactivation of theoptical communication interface 103 a is stored in a register RR0corresponding to an address BASE+0 viewed from the user control device's102 side. The communication protocol module 107 a always reads controlinformation stored in the register RR0, and based on this information itcontrols activation or deactivation of the optical communicationinterface 103 a. Therefore, the control information FA is always storedin the register RR0; the user control device 102 sends the controlinformation FA by designating the address BASE+0 corresponding to theregister RR0; the communication protocol module 107 a acquires thecontrol information FA from the register RR0. Similarly, controlinformation PA which controls the activation or deactivation of each ofthe interfaces 104 a to 106 a is always stored in a register RR1; theuser control device 102 stores the control information PA by designatingan address BASE+1 corresponding to the register RR1; the communicationprotocol module 107 b acquires the control information PA from theregister RR1 and controls the activation or deactivation of each ofinterfaces 104 a to 106 a. Moreover, control information PL for loopbackprocessing of each of the interfaces 104 a to 106 a, control informationAB for audio bandwidth, control information DB for data bandwidth, andcontrol information VB for video bandwidth are always stored inregisters RR2 to RR5, respectively; the user control device 102 storescontrol information PL, AB, DB and VB by designating addresses BASE+2 toBASE+5 corresponding to the registers RR2 to RR5; the communicationprotocol module 107 c acquires the control information PL from theregister RR2 and controls the loopback processing; the communicationprotocol module 107 d acquires the control information AB, DB and VBfrom the registers RR3 to RR5 and controls the set-up processing ofbandwidth used for audio, data and video. This communication protocol107 d corresponds to three registers RR3 to RR5, because the bandwidthset-up cannot fit into one register as a unit of information containableby each register RR is fixed. However, the control information stored inthe registers RR3 to RR5 are fixed.

In the above mentioned conventional communication system 100, since allcontrol information is stored in the fixed space of registers RR, if thecommunication protocol is modified, additional registers which storecontrol information for this modification need to be assigned and due tothis addition of registers, in some cases the position of the registersalready assigned for the storage of control information needs to bechanged.

If the positions of these existing registers are changed, the usercontrol device 102 needs to change register-position indicatingaddresses for all control information that it sends, thus the usercontrol device 102's address space for accessing control informationwill have to be modified which requires a complicated operation andcauses problems.

Moreover, in the implementation of communication protocol (FIG. 10),since the position of the registers which acquire control information ischanged, the position of registers for the implementation of theexisting communication protocol also has to be changed. Especially, whenthe communication protocol is complicated, a lot of time needs to bespent for such modifications, a lot of time and labor are also requiredfor debugging since it is difficult to organize the relative positionsof registers, which sacrifices time and labor required for theimplementation of the communication protocol and causes problems.

For example, FIG. 11 illustrates the main structure of a communicationdevice which is formed by adding two communication functions(implemented by 107 e and 107 f) to the structure of the communicationdevice described in FIG. 10. The block 107 e added in FIG. 11 is a blockfor selection processing of the audio coding algorithm using controlinformation AC. The block 107 f is a block for compression processing ofdata using control information DM. In this case, since the selection ofaudio coding algorithm deals with audio data, the control information ACshould be placed in a register close to the control information AB whichsets up audio bandwidth; and since the compression of data deals withdata, the control information DM should be placed in a register close tothe control information DB which sets up data bandwidth. Therefore, thecontrol information AC and the control information DM are inserted intothe register RR4 and the register RR6 respectively. As a result, thecontrol information DB which was placed in the register RR4 is moved tothe register RR5, and the control information VB which was placed in theregister RR5 is moved to the register RR7. Thus due to the changes inregisters the control device 102's addresses also need to be modified.Moreover, among the already set up blocks 107 a to 107 d, 107 d need tobe modified; the register RR4 shifted to the register RR5, and theregister RR5 shifted to the register RR7. Thus changes to thecommunication protocol triggers the following major modifications:modifications to the positions of the registers, modifications to theuser control device 102's addresses, and modifications to the routingbetween the other implementation blocks and the registers.

Moreover, when changes to the communication protocol are implemented,mistaken routing between the implementation blocks and the registerscauses the implementation blocks to acquire irrelevant controlinformation, thus causing malfunction and causes big problems.

On the other hand, due to rapid technological advances recently, thedevelopment cycle of communication devices has shortened, and the designmodification cycle has also shortened, there is a continuous demand fora reduction in time and labor spent on design changes.

DISCLOSURE OF THE INVENTION

This invention solves the above mentioned problems, reduces the time andlabor necessary for design changes such as adding or deletingcommunication protocol modules, thoroughly eliminates malfunctionality,and provides a communication system with a flexible communicationdevice.

In order to achieve the above mentioned objectives, the first inventionis a communication system comprising a control device, one or morecommunication terminals, and a communication device which connects thecontrol device with the one or more communication terminals, and has oneor more communication protocol modules for controlling communications ofthe one or more communication terminals based on control informationfrom the control device, characterized in that the communication deviceincludes: a memory which temporarily stores the control information sentfrom the control device, sequentially; control information acquisitionmeans which sequentially acquires the control information temporarilystored in the memory and broadcasts it to the one or more communicationprotocol modules; and one or more detection means each being provided incorrespondence with each of the one or more communication protocolmodules at a front stage on an input side of each of the communicationprotocol modules, for detecting whether the control informationbroadcasted by the control information acquisition means needs to beprocessed by each of the one or more communication protocol modules, andthat the one or more communication protocol modules implement processingof the control information if a corresponding one or more detectionmeans detect that the control information is meant to be processed by anown communication protocol module.

In the first invention, the position of the control information in thememory is not fixed; the control information acquisition means reads thecontrol information from the memory and broadcasts it to each of thedetection means; only if one or more detection means detect that thecontrol information should be processed by its correspondingcommunication protocol module, each of such detection means sends thenecessary information needed by its communication protocol module to it,thus each of the communication protocol modules implements processes,and so the communication device design can be modified by just theaddition or deletion of communication protocol modules.

Since the communication device design can be changed by just adding ordeleting communication protocol modules, the time and labor necessaryfor changes to design can be significantly reduced.

Moreover, addresses of the control information in the control devicedon't need to correspond to memory locations in the communicationdevice; there is no need to change the control device design inaccordance with changes to the implemented design of the protocol torealize modifications to the communication protocol.

Since each of the communication protocol modules is designed to docommunication protocol processing irrelevant to the memory space, thereis no need to modify the design of the communication protocol modulessuch as address changes, as a result of the addition or deletion ofcommunication protocol modules.

The second invention is characterized in that, in the first invention,the control information acquisition means and the one or more detectionmeans corresponding to the one or more communication protocol modulesare connected through a bus.

In the second invention, the control information acquisition meansbroadcasts the control information through a bus; one or more detectionmeans placed at the front stage of each of the communication protocolmodules only detect control information meant for their correspondingcommunication protocol modules, thus wrong control information will notbe input to any of the communication protocol modules, preventingmalfunctions and breakdowns.

The third invention is characterized in that, in the first and thesecond inventions, each of the one or more communication protocolmodules is constituted for each of the processing categories of thecontrol information.

In the third invention, since the control information corresponds to oneor more communication protocol modules, when adding or deletingcommunication protocol processes, the communication device design can bechanged by just adding or deleting the corresponding communicationprotocol module or modules.

The fourth invention is characterized in that, in the first to thirdinventions, the memory has a control space for temporarily storingcontrol information from the control device to the one or more protocolmodules and a status space for temporarily storing status informationfrom the one or more protocol modules to the control device, and thatthe control device writes control information into the control space ofthe memory and reads status information from the status space of thememory.

In the fourth invention, bi-directional communication can be achieved bysending control information and receiving status information through thememory, thus operability for communication device's processing by thecontrol device can be improved.

The fifth invention is characterized in that, in the fourth invention,the control information written to the control space is comprised of acommand number and command data; and that the control device temporarilystores at least a pair of the command number and the command data intothe memory sequentially.

In the fifth invention, the command number and command data are storedinto the memory separately, each detection means can judge quicklywhether the control information is related to its communication protocolmodule based on the command number.

The sixth invention is characterized in that, in the fifth invention,the control space is comprised of a command space which consists ofpairs of the command number and the command data both made up of a fixedunit of information and a data space for temporarily storing the commanddata if the command data exceeds the fixed unit of information; and thatthe control device writes information corresponding to an address withinthe data space where the command data is temporarily stored, instead ofthe command data that pairs with the command number, and also writes toa head of the command data stored in the data space informationcorresponding to a data length, in the fixed unit of information, inwhich a content of the command data is temporarily stored.

In the sixth invention, basically search of control information can beconducted quickly since pairs of command number and command data made upof fixed unit of information are stored in the memory in principle.

The seventh invention is characterized in that, in the sixth invention,the information which corresponds to the address written in the fixedunits of information and the information which corresponds to the datalength, both are a virtual address or a virtual data length formed byshifting values by a fixed amount; and that the control device processesthe virtual address or the virtual data length both as reverse shiftedby a fixed amount.

In the seventh invention since a virtual address and a virtual datalength are employed, even though a fixed unit of information is used,large addresses and large data lengths can be handled, thus a flexiblesystem can be built, since it can maintain a fixed unit of information,fast retrieval of control information also becomes possible.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block diagram of a rough structure of an embodiment of acommunication system of the invention;

FIG. 2 illustrates a relationship between an address space of a controldevice 2 and a memory space of a communication device 1;

FIG. 3 depicts a relationship between a command space and a data space;

FIG. 4 illustrates a detailed structure of the command space and thedata space;

FIG. 5 shows a flow chart of processing sequence of a commandacquisition unit 8;

FIG. 6 illustrates a block diagram of processing of control informationin the communication device employing the embodiment of this invention;

FIGS. 7( a) and 7(b) depict actual contents of data in the command spaceand the data space;

FIG. 8 shows a structure of the communication device in FIG. 6 after itsdesign is changed;

FIG. 9 illustrates an example of a communication system including acommunication device;

FIG. 10 depicts a relationship between registers and communicationprotocol implementation blocks in a conventional communication device;and

FIG. 11 shows a structure of the conventional communication device inFIG. 10 after its design is changed.

BEST MODE FOR CARRYNG OUT THE INVENTION

The following explains preferred embodiments of this invention byreferring to figures:

FIG. 1 shows a block diagram of an embodiment of a communication systemof this invention. In FIG. 1 a control device 2 is connected to acommunication device 1 through which it controls multiple communicationterminals 3-1 to 3-n which are connected to the communication device 1.And the connection between the communication terminals 3-1 to 3-n andthe communication device 1 constitutes a communication network.

The communication device 1 is mainly composed of a control deviceinterface 4, a communication protocol engine 5, and communicationnetwork interfaces 6-1 to 6-n.

The control device interface 4 comprises a memory 7, a commandacquisition unit 8 and multiple detection units 9-1 to 9-m. The controldevice 2 writes control information sent out by it to the memory 7 andreads status information from the memory 7. Logically a control space Eato store the control information and a status space Eb to store thestatus information coexist inside the memory 7. And the control space Eahas two areas, namely a command space E1 and a data space E2. Thecommand space E1 comprises pairs made up of command numbers and commanddata, which are stored sequentially via access from the control device2. In case the command data cannot fit in memory 7 width-wise, thiscommand data stores data address information of the data space E2 thatstores the command data that could not be expressed in the memory 7width-wise, and it serves as a pointer. In other words, only when thecommand data is larger than the width of the memory 7, the data space E2is used. The structure of the status space Eb is fixed and informs thecontrol device of execution results of each command from thecommunication protocol. The detailed structure of the memory 7 isexplained later.

The command acquisition unit 8 and the multiple detection units 9-1 to9-m are connected with a back-end bus 12. Each detection unit 9-1 to 9-mcorresponds respectively to each of multiple communication protocolmodules 10-1 to 10-m inside the communication protocol engine 5 whichperform communication processing corresponding to each command; and eachdetection unit 9-1 to 9-m and each communication protocol module areconnected individually.

The command acquisition unit 8 automatically retrieves the controlinformation temporarily stored in the memory 7 and broadcasts theretrieved control information to each detection unit 9-1 to 9-m throughthe back-end bus 12. Each detection unit 9-1 to 9-m receives the controlinformation broadcasted through the back-end bus 12, decodes the commandnumber, detects if the decoded result is meant for a communicationprotocol module corresponding to own detection unit, and sends out thiscontrol information to own communication protocol module only if thiscontrol information is meant for the communication protocol module thatcorresponds to own detection unit. On the other hand, each detectionunit 9-1 to 9-m ignores the control information if the decoded result isnot meant for the communication protocol module that corresponds to owndetection unit.

The communication protocol engine 5 comprises the multiple communicationprotocol modules 10-1 to 10-m and a communication protocol managementunit 11 which controls the communication protocol modules 10-1 to 10-m.As stated above each communication protocol module 10-1 to 10-m performscommand processing according to command number. Therefore, eachcommunication protocol module 10-1 to 10-m does not necessarily performprocessing corresponding to a specific communication terminal 3-1 to3-n. Each communication protocol module 10-1 to 10-m receives controlinformation or information necessary for processing of own communicationprotocol module, for instance command data, from the detection unit 9-1to 9-m connected in correspondence with own communication protocolmodule, and carries out predetermined communication protocol processing.Thus, each communication protocol module 10-1 to 10-m can carry outcommunication protocol processing irrespective of where controlinformation which corresponds to it is stored in the memory. Dependingon the result of communication protocol processing the communicationprotocol management unit 11 by means of Bus 13 manages and processesdata which flows through the connection media located in-between thecommunication network interfaces 6-1 to 6-n and the communicationterminals 3-1 to 3-n corresponding respectively to each one of theseinterfaces.

In this way, in the communication device 1 described in FIG. 1, thecontrol information stored in the memory 7 is not stored in fixedlocations but stored sequentially in the order in which it is sent fromthe control device 2. Thus for example, if new communication controlprocessing becomes necessary due to connecting new communicationterminal 3-(n+1) to the communication device 1, the communicationterminal 3-(n+1) can be controlled just by adding a new communicationnetwork interface 6-(n+1), a new communication protocol module 10-(m+1)corresponding to the new control information, and detection unit9-(m+1); regardless of the location of this new control information inmemory. The control device 2 on the other hand just needs to send newcontrol information to the communication device 1 and in spite ofaddition of new control data, is not required to change the address ofother control information necessitated by a change in memory locations.

The communication protocol module 10-(m+1) does not require anyinformation regarding the location of new control information in thememory 7, other communication protocol modules 10-1 to 10-m never hadany information regarding memory 7's locations from the beginning; thusadjustment to the memory locations caused by adding the newcommunication protocol module 10-(m+1) is not necessary.

Furthermore, the same procedure as outlined above is followed whenadding new control information i.e. command pertaining to the existingcommunication terminals 3-1 to 3-n without the addition of a newcommunication terminal 3-(n+1). In such a case, the only thing requiredis to add a detection unit 9-(m+1) corresponding to the command and acommunication protocol module 10-(m+1) which processes this command.

Next, an explanation of the data structure stored in the memory 7 usingreference FIGS. 2 to 4 follows.

FIG. 2 shows a relationship between an address space E0 in the controldevice 2 and a memory space E in the memory 7. In FIG. 2 addressesBASE+0 to BASE+m of control and status information sent out by thecontrol device 2 can use the address space E0 in the control device 2arbitrarily. As stated above, the control information is written to thecontrol space Ea by the control device 2, and the status information isread from the status space Eb by the control device 2. The control spaceEa and the status space Eb logically divide the memory space E, and itis possible for them to coexist together. Moreover, the control device 2side can access the memory 7 as a memory space E that corresponds to anarbitrary address space E0.

FIG. 3 shows the command space E1 and the data space E2 which composethe control space Ea. Even though in FIG. 3 the control space Ea iscomprised of the command space E1 and the data space E2, if data for acommand is smaller than the width of the memory 7, data byte DB thatcomposes the command space E1 is used instead of the data space E2.

As FIG. 4 shows the command space E1 is a space in which pairs ofcommand bytes CB of the memory 7 width and data bytes DB of the memory 7width are described consecutively. In other words, the command space E1is a space in which the command bytes CB and the data bytes DB appearalternately Therefore, the control information composed of the commandbyte CB of the memory 7 width and the data byte DB of the memory 7 widthis at least twice the width of the memory 7. For example, controlinformation comprised of command byte CB(1) and data byte DB(1) iswritten to two memory 7 widths of the memory space E namely #2 and #3corresponding to addresses BASE+2 and BASE+3 in the address space E0respectively.

If the width of the memory 7 is B bits then the width of the commandbyte CB shall be 8*B bytes. Bit (8*B−1) of the command byte CB hasinformation that indicates whether or not next control informationexists. If this bit is a “1”, it indicates that control informationexists in a next byte in the memory space consecutively; else if it is a“0”, it indicates that there is no control information existing in thenext byte consecutively, which means that this control information isthe last one in the control information set received. Bits (8*B−2),(8*B−3) contain information representing the command type; “00”indicating command type 0, and “01” indicating command type 1. Thecommand type 0 shows that command data is smaller than or equal to Bbytes, and that the command data itself is stored in the counterpart,data byte DB. The command type 1 shows that the command data is largerthan B bytes and the counterpart data byte DB stores the address of thedata space E2 which stores the command data, and functions as a pointer.The command type “10” or “11” is reserved for future extensions. Bits(8*B−4) to 0 show the command number itself and function as a (8*B−3)command identifier.

In case the command data is larger than B bytes, for instance, if thecommand data of a command byte CB(i) is (2*B) bytes, the address of thedata space E2 which stores this (2*B) byte command data is expressedusing B bytes as a data address in the data byte DB(i). This addressshows the address which stores the data length of the command data inthe data space E2. As for the command data in the data space E2, thedata length of the command data is stored in its first byte. Forexample, if B is 1, and the data length is 2 bytes, then ‘00000010’ isstored in the data length.

However, if the data byte DB has a large address value which cannot beexpressed in (8*B) bits, then the control device 2 needs to decide uponan address-shift value in advance, and a virtual address formed,considering this fixed address-shift value, needs to be stored into thedata byte DB. By using such a virtual address, large address values canbe assigned. For example, if B is 1 and the real address is expressed asa 9 bit value, the virtual address that was formed by right-shifting by1 bit beforehand, should be stored in the data byte DB, and this virtualaddress should be shifted to the left by 1 bit when the real address inthe data space is sought. In consequence, large address values can behandled.

Similarly, large values can be realized for the data length in the dataspace E2 by converting them to virtual data lengths. For instance, if Bis 1, and data length is expressed by 9 bits, a virtual data lengthformed beforehand by right-shifting by 1 bit could be stored as the datalength, and this virtual data length could be shifted to the left by 1bit to compute the real data length. As a consequence, large commanddata can be stored.

However, the above mentioned virtual address and virtual data lengthneed to be supersets of the real address or real data lengthrespectively. Because of using such margin-embedded virtual address andvirtual data length, even though the memory is not fully utilized, yetthe command byte CB and the data length can always be expressed withinthe width of the memory 7, and thus speedier reading of the memory 7 canbe achieved.

The shift amounts of the aforementioned address and data length are setin the communication device 1 in advance, and the shift amount of theaddress and that of the data length can be set to either the same ordifferent values.

Next, referring to the flow chart of FIG. 5, the processing sequence ofthe command acquisition unit 8 is explained.

In FIG. 5, first of all the command acquisition unit 8 checks whether itis a command acquisition time or not (step S1). This step is neededbecause the control device 2 and the communication protocol engine 5share the memory 7, or in other words because it is necessary toseparate the time when the control device 2 writes the controlinformation and the time when the command acquisition unit 8 reads thecontrol information (command acquisition time). Likewise, it isnecessary to separate the writing and reading of the status information,but could be done in the same way as in case of the control information.The switching of the command acquisition time can be achieved usingalready known interrupt control or time division based control methods.When the interrupt control is employed, a changeover can be facilitatedwhen an interrupt occurs at the end of each write or read process. Onthe other hand, when the time division based control is used, thecontrol device 2 and the command acquisition unit 8 need to besynchronized. When this time division based control is used, the controldevice 2 must write the control information to the memory 7 each time,however if it does not have any control information, then a null commandwhich is commonly known as a command with no function must be used. Byusing this null command, the control information can be defined as ofthe command type 0.

In any case, if it is determined as the command acquisition time in stepS1, the command acquisition unit 8 reads the command byte CB and thedata byte DB from the command space E1 (step S2) and then checks if thecommand type is “0” or “1” (step S3). If the command type is “0”, thecommand data is expressed in the data byte DB, thus this command data isbroadcasted on the back-end bus 12 along with the command number (stepS4).

Subsequently, whether the next control information exists is checkedreferring to the value of bit (8*B−1) of the command byte CB (step S5).If bit (8*B−1) is “1” and thus the control information exists in thenext byte, a move to step S3 is performed and the aforementioned stepsfrom step S3 are repeated (step S6); if bit (8*B−1) is “0” and thus nocontrol information exists in the next byte, a move to step S1 isperformed and the aforementioned steps from step S1 are repeated.

On the other hand, if in step S3 the command type is determined to be“1”, the value of the data byte DB is bit-shifted by an address-shiftamount set in advance (step S7), and the control transfers to thisshifted real address (step S8). Furthermore, the data length recorded inthe byte at this real address is bit-shifted by a data length shiftamount set in advance (step S9), the command data equaling this realdata length is read (step S10), and at the same time this read commanddata along with the command number is broadcasted on the back-end bus 12(step S11), a move to step S5 is performed and the aforementioned stepsfrom step S5 are repeated.

In this fashion, the command acquisition unit 8 automatically reads outthe control information regardless of a random order in which thecontrol device 2 has stored it into the memory space, and broadcasts itto each detection unit 9-1 to 9-m corresponding to each communicationprotocol module 10-1 to 10-m. This broadcasted control information is,as described above, sent to own communication protocol module andprocesses are implemented, only when each detection unit 9-1 to 9-mdetects that the control information is related to own communicationprotocol module corresponding to own detection unit.

Next, explained below is an example of a communication system having acommunication device, as shown in FIG. 9, to which the idea of thisinvention is applied. Therein, a user control device 102 corresponds tothe control device 2, a communication device 101 to the communicationdevice 1, and a communication network 103, an audio processing device104, a data processing device 105 and a video processing device 106 tothe communication terminals 3-1 to 3-n. Furthermore, a user interface102 a corresponds to the control device interface 4, a communicationprotocol engine 107 to the communication protocol engine 5, and anoptical communication interface 103 a, an audio interface 104 a, a datainterface 105 a and a video interface 106 a to the communication networkinterfaces 6-1 to 6-n. Therefore, the user interface 102 a contains thememory 7, the command acquisition unit 8, the back-end bus 12 and thedetection units 9-1 to 9-m; and the communication protocol engine 107contains the communication protocol management unit 11 and thecommunication protocol modules 10-1 to 10-m. Other structural parts willbe explained using the same numbering as shown in FIG. 9.

If a communication system ST of this invention is applied to thecommunication system 100 in FIG. 9, the implementation of a controlinformation processing block in the communication device 1 of FIG. 1shall be as shown in FIG. 6. In other words, FIG. 6, applying thisinvention, achieves the same function as of FIG. 10, the internalorganization of the memory 7 is not fixed, and is just divided into thecommand space E1 and the data space E2. In FIG. 6, the fourcommunication protocol modules 10-1 to 10-4 implement the same functionas the communication protocol modules 107 a to 107 d in FIG. 10,implementing activation/deactivation processing of the opticalcommunication interface 103 a, activation/deactivation processing ofeach interface 104 a to 106 a, loopback processing of each interface 104a to 106 a, and set-up processing of bandwidth used, respectively. Alsothe detection units 9-1 to 9-4 are set-up corresponding to thecommunication protocol modules 10-1 to 10-4 respectively. The commandacquisition unit 8 broadcasts the control information obtained from thememory 7 to each detection unit 9-1 to 9-4 through the back-end bus 12.On the back-end bus 12, control signals indicating the controlinformation, contents of the command byte CB, and of the data byte DB(includes data length if necessary) are broadcasted. Each detection unit9-1 to 94 upon detecting a command meant for its correspondingcommunication protocol module 10-1 to 10-4 respectively, sends out theinformation necessary for processing by each communication protocolmodule 10-1 to 10-4 to each communication protocol module 10-1 to 10-4for processing.

Now, the structure of the related command byte CB is explained. Thecontrol information comprises the above mentioned null command and fourother commands corresponding to the communication protocol modules 10-1to 10-4. For this explanation, the width B of the memory 7 is supposedto be one byte.

The null command is of command type “00” and command number “00000”, theactivation/deactivation command of the optical communication interface103 a is of command type “00” and command number “00001”, theactivation/deactivation command of each interface 104 a to 106 a is ofcommand type “00” and command number “00010”, the loopback command ofeach interface 104 a to 106 a is of command type “00” and the commandnumber “00011”, and control command for bandwidth used is of commandtype “01” and command number “00100”. These command numbers are commonlyused for the user control device 102's side.

The data byte DB of the null command is made up of all arbitrary bits.

The data byte DB for the activation/deactivation command of the opticalcommunication interface 103 a instructs activation when bit 0 is “1” andinstructs deactivation when bit 0 is “0”. All other bits are set uparbitrarily.

In case of the data byte DB for the activation/deactivation command ofeach of the interfaces 104 a to 106 a, the video interface 106 a is thetarget of control when bit 7 is “1”, the data interface 105 a is thetarget of control when bit 6 is “1” and the audio interface 104 a is thetarget of control when bit 5 is “1”; activation for each targetedinterface is instructed when bit 0 is set to “1”. All other bits are setup arbitrarily.

With regards to the data byte DB for the loopback command for each ofthe interfaces 104 a to 106 a, the video interface 106 a is the targetof control when bit 7 is “1”, the data interface 105 a is the target ofcontrol when bit 6 is “1”, the audio interface 104 a is the target ofcontrol when bit 5 is “1”; loopback processing for each targetedinterface is instructed when bit 0 is set to “1”.

For the data byte DB for the control command of the bandwidth used,address to store the command data is instructed, and the four-bytecommand data is stored at this instructed address in the data space. Inthe first byte, “00000011” representing a three-byte data length isstored, in the second byte, the data for the audio bandwidth used isstored, in the third byte, the data for the data bandwidth used isstored, and in the fourth byte, the data for the video bandwidth used isstored. In each byte, figures representing percentages of bandwidth usedare indicated using upper four bits and lower four bits, and the totalof bandwidth used of each byte should sum up to 100%. For example, ifaudio bandwidth used is 25%, it should be represented by “00100101”.

Now, for a more concrete explanation of the command space and the dataspace for control information, FIG. 7( a) shows the contents of thecommand space for the case when the video interface 106 a is deactivatedand loopback of the audio interface 104 a and the data interface 105 ais instructed.

In FIG. 7( a), “10000010” is written to the command byte CB0 and“10000000” is written to the data byte DB0 in the command space E1,which correspond respectively to BASE+0 and BASE+1 in the address spaceof the user control device 102. Bit 7 of the command byte CB0 is “1”,which indicates that there is control information in the next byte. Thecommand number of the command byte CB0 is “00010”, which indicates theactivation/deactivation command for each of the interfaces 104 a to 106a. The fact that bit 7 of the data byte DB0 is a “1” indicates anactivation/deactivation command for the video interface 106 a, and thefact that bit 0 is a “0” indicates that the deactivation of the videointerface 106 a is instructed.

Furthermore, “00000011” is written to the command byte CB1 and“01100001” is written to the data byte DB1 in the command space E1,which correspond respectively to BASE+2 and BASE+3 in the address space.As bit 7 of the command byte CB1 is “0”, it shows that no controlinformation exists in the next byte and that this is the last controlinformation. Also, the fact that the command number is “00011” indicatesthat this is a loopback processing command for each of the interfaces104 a to 106 a. As both bit 6 and bit 5 of the data byte DB1 are “1”,instructions for the data interface 105 a and the audio interface 104 aare indicated respectively, and as bit 0 is “1”, it shows that this is aloopback instruction for the data interface 105 a and the audiointerface 104 a.

Similarly according to the address space in FIG. 7( b) deactivation isinstructed using the activation/deactivation command for the opticalcommunication interface 103 a, and setting of each bandwidth used isinstructed using the control command for the bandwidth used. Eachbandwidth used is instructed using three bytes inside the data space E2;and an audio bandwidth to be set to 15%, a data bandwidth to be set to50%, and a video bandwidth to be set to 35% is instructed. In the databyte DB1 the relative address value in the address space E2 is stored,right-shifted by 1 bit in advance, and this address value is convertedto an address value shifted to the left by 1 bit during read. And allthe bit values hidden due to shifting shall be set to “0”.

Here, referring to FIG. 8, the structure in case of a design change, thesame as shown in FIG. 11 is explained. In other words, the case in whichthe communication protocol module 10-5 for the selection processing ofaudio coding algorithm and the communication protocol module 10-6 fordata compression processing are added, is explained. Each of thecommunication protocol modules 10-5 and 10-6 has detection units 9-5 and9-6 respectively, same as the communication protocol modules 10-1 to10-4. And each of the detection units 9-5 and 9-6 is commonly connectedto the back-end bus 12. Thus, each detection unit 9-1 to 9-6 receivesthe control information broadcasted from the command acquisition unit 8,and if this control information is meant for own communication protocolmodule corresponding to own detection unit, the information needed forprocessing by own communication protocol module is sent to owncommunication protocol module for processing.

In this case, the user control device 102 sends the audio codingalgorithm selection processing command or the data compressionprocessing command to the communication device 101 by using just acommon command and data byte format, thus there is no need to establisha relationship between the address space of the user control device 102and the memory space inside the memory. Since the command acquisitionunit 8 just reads the contents of the memory space sequentially andbroadcasts them on the back-end bus 12, there is no need for designchanges to the command acquisition unit 8. Moreover, since each of thecommunication protocol modules 10-1 to 10-6 performs processingirrelevant to the position of the address space, there is no need tomodify any of the communication protocol modules 10-1 to 10-6 either.Therefore, it is possible to improve upon the functionality ofcommunication control processing by simply adding the communicationprotocol modules 10-5 and 10-6, and their corresponding detection units9-5 and 9-6, to implement a communication system with a general-purposecommunication device.

If a communication protocol module corresponding to the controlinformation acquired by the command acquisition unit 8 doesn't exist,each of the detection units 9-1 to 9-6 detects that the controlinformation doesn't relate to their communication protocol modules, andthe control information is not sent to each of the communicationprotocol modules 10-1 to 10-6, and no operation is executed for thiscontrol information. As a result, no malfunction is caused byinstructions from erroneous control information, early prevention ofbreakdown can be achieved.

The implementation of this invention has the flexibility that even ifthe controlling device like the user control device which controls thecommunication device is replaced, the communication control processingcan be correctly achieved just by inputting similar control informationto the communication device. In this case, as mentioned above, if nocommunication protocol module to process the corresponding controlinformation exists, the process of the communication protocol won't beexecuted.

INDUSTRIAL APPLICABILITY

This invention relates to a communication system which enables aremarkable reduction in time and labor required to modify a design of acommunication device in accordance with a revision in a communicationprotocol. According to this invention, a position of control informationin a memory is not fixed; control information acquisition means readsthe control information from the memory and broadcasts it to each ofdetection means; if one or more detection means detect that the controlinformation should be processed by own communication protocol modulecorresponding to own detection means, each of such detection means sendsnecessary information needed by each communication protocol module toeach communication protocol module, thus each of the communicationprotocol modules implements processes, and so a communication devicedesign can be modified by just addition or deletion of communicationprotocol modules, which is a merit of this invention.

Since the communication device design can be changed by just adding ordeleting communication protocol modules, time and labor necessary forchanges to design can be significantly reduced, which is also a merit ofthis invention.

Moreover, addresses of the control information in the control devicedon't need to correspond to memory locations in the communicationdevice; when changes are implemented, change in the design of thecontrol device is carried out just by adding or modifying commands anddata corresponding to the added or modified communication protocolmodules, to a group of commands and data which is transmittable from thecontrol device to the communication device, which is a merit of thisinvention.

Since each of the communication protocol modules is designed to docommunication protocol processing irrelevant to the memory space, thereis no need to modify the design of the communication protocol modulessuch as address changes, as a result of the addition or deletion ofcommunication protocol modules, which is a merit of this invention.

Moreover, reading out of control information and so on can be conductedquickly since control information made up of fixed unit of informationare stored in the memory, which is a merit of this invention.

Also, since each of the communication protocol modules has its owndetection means which only carries out processes corresponding to itscommunication protocol module, input or reception of erroneous controlinformation doesn't cause malfunctions and thus early prevention ofbreakdown can be achieved, which is also a merit of this invention.Because of this, when changes or additions to the communication protocolare implemented, the development of the modification or addition to thecommunication protocol module and the modification or addition to thegroup of commands and data in the control device can be carried outseparately, which is a merit of this invention.

1. A communication system comprising a control device, a plurality ofcommunication terminals, and a communication device which connects thecontrol device with the plurality of communication terminals and has aplurality of communication protocol modules for controllingcommunications of the plurality of communication terminals based oncontrol information from the control device, the communication deviceincluding: a memory which temporarily stores the control informationsent sequentially from the control device; control informationacquisition means which sequentially acquires the control informationtemporarily stored in the memory and broadcasts it to the one or morecommunication protocol modules; a plurality of detection means eachbeing provided in correspondence with each of the plurality ofcommunication protocol modules at a front stage on an input side of eachof the communication protocol modules for detecting whether the controlinformation broadcasted by the control information acquisition meansneeds to be processed by the plurality of communication protocolmodules; the plurality of communication protocol modules implementprocessing of the control information if a corresponding one of theplurality of detection means detect that the control information ismeant to be processed by a communication protocol module; the memoryhaving a control space for temporarily storing control information fromthe control device to the protocol modules and a status space fortemporarily storing status information from the protocol modules to thecontrol device; the control device writes the control information intothe control space of the memory and reads the status information fromthe status space of the memory; the control information written to thecontrol space includes a command number and command data; and thecontrol device temporarily stores at least a pair of the command numberand the command data in the memory sequentially.
 2. A The communicationsystem according to claim 1 characterized in that: the control space iscomprised of a command space which consists of pairs of the commandnumber and the command data both made up of a fixed unit of informationand a data space for temporarily storing the command data if the commanddata exceeds the fixed unit of information and a data space fortemporarily storing the command data if the command data exceeds thefixed unit of information, and the control device, if the command dataexceeds the fixed unit of information, writes information correspondingto an address within the data space where the command data istemporarily stored, instead of the command data that pairs with thecommand number, and also writes to a head of the command data stored inthe data space information corresponding to a data length in the fixedunit of information, in which a content of the command data istemporarily stored.
 3. A The communication system according to claim 2characterized in that: the information which corresponds to the addresswritten in the fixed units of information and the information whichcorresponds to the data length, both are a virtual address or a virtualdata length formed by shifting values by a fixed amount, and the controldevice processes the virtual address or the virtual data length as anaddress or a data length that was reverse shifted by a fixed amount. 4.A communication system comprising a control device, a plurality ofcommunication terminals and a communication device which connects thecontrol device with the plurality of communication terminals and has aplurality of communication protocol modules for controllingcommunications of the plurality of communication terminals based oncontrol information from the control device; the communication deviceincluding, a memory which receives the control information sent from thecontrol device and stores the received control information sequentiallyand in parallel form; control information acquisition means forsequentially acquiring from the memory the temporarily stored controlinformation and broadcasting the control information to the plurality ofcommunication protocol modules on a parallel bus; a plurality ofdetection means each corresponding to an associated one of the pluralityof communication protocol modules at a front stage on an input side ofeach of the communication protocol modules for detecting whether thecontrol information broadcasted by the control information acquisitionmeans needs to be processed by at least one of the communicationprotocol modules; and at least one of the communication protocol modulesimplements processing of the control information if a corresponding oneof the detection means detect that the control information is meant tobe processed by the corresponding communication protocol module.
 5. AThe communication system according to claim 4 characterized in that thecontrol information acquisition means and the direction meanscorresponding to the communication protocol modules are connectedthrough a parallel bus.
 6. A The communication system according to claim4 characterized in that each of the communication protocol modules areconstructed and arranged for processing categories of the controlinformation.
 7. A The communication system according to claim 4characterized in that: the memory has a control space for temporarilystoring control information from the control device to the protocolmodules and a status space for the temporarily storing statusinformation from the protocol modules to the control device, and thecontrol device writes the control information into the control space ofthe memory and reads the status information from the status space of thememory.
 8. The communication system according to claim 5 characterizedin that each of the communication protocol modules is constructed andarranged for processing categories of the control information.
 9. Thecommunication system according to claim 5 characterized in that: thememory has a control space for temporarily storing control informationfrom the control device to the protocol modules and a status space fortemporarily storing status information from the protocol modules to thecontrol device, and the control device writes the control informationinto the control space of the memory and reads the status informationfrom the status space of the memory.
 10. The communication systemaccording to claim 6 characterized in that: the memory has a controlspace for temporarily storing control information from the controldevice to the protocol modules and a status space for temporarilystoring status information from the protocol modules to the controldevice, and the control device writes the control information into thecontrol space of the memory and reads the status information from thestatus space of the memory.
 11. The communication system according toclaim 4 characterized in that: the control information written to thecontrol space includes a command number and command data; and thecontrol device temporarily stores at least a pair of the command numberand the command data in the memory sequentially.
 12. The communicationsystem according to claim 11 characterized in that: the control space iscomprised of a command space which consists of pairs of the commandnumber and the command data both made up of a fixed unit of informationand a data space for temporarily storing the command data if the commanddata exceeds the fixed unit of information and a data space fortemporarily storing the command data if the command data exceeds thefixed unit of information, and the control device, if the command dataexceeds the fixed unit of information, writes information correspondingto an address within the data space where the command data istemporarily stored, instead of the command data that pairs with thecommand number, and also writes to a head of the command data stored inthe data space information corresponding to a data length in the fixedunit of information, in which a content of the command data istemporarily stored.
 13. The communication system according to claim 12characterized in that: the information which corresponds to the addresswritten in the fixed units of information and the information whichcorresponds to the data length, both are a virtual address or a virtualdata length formed by shifting values by a fixed amount, and the controldevice processes the virtual address or the virtual data length as anaddress or a data length that was reverse shifted by a fixed amount.